Correctify instanceof and make it optimizable.

src/v8natives.js

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 (function(global, utils) {
 
 %CheckIsBootstrapping();
 
 // ----------------------------------------------------------------------------
 // Imports
@@ skipping 175 matching lines @@
     var handler = %GetHandler(object);
     return CallTrap1(handler, "hasOwn", ProxyDerivedHasOwnTrap, name);
   }
   return %HasOwnProperty(object, name);
 }
 
 
 // ECMA-262 - 15.2.4.6
 function ObjectIsPrototypeOf(V) {
   if (!IS_SPEC_OBJECT(V)) return false;
-  CHECK_OBJECT_COERCIBLE(this, "Object.prototype.isPrototypeOf");
-  return %IsInPrototypeChain(this, V);
+  var O = TO_OBJECT(this);
+  return %_HasInPrototypeChain(V, O);
 }
 
 
 // ECMA-262 - 15.2.4.6
 function ObjectPropertyIsEnumerable(V) {
   var P = $toName(V);
   if (%_IsJSProxy(this)) {
     // TODO(rossberg): adjust once there is a story for symbols vs proxies.
     if (IS_SYMBOL(V)) return false;
 
@@ skipping 1602 matching lines @@
 });
 
 utils.ExportToRuntime(function(to) {
   to["global_eval_fun"] = GlobalEval;
   to["object_define_own_property"] = DefineOwnPropertyFromAPI;
   to["object_get_own_property_descriptor"] = ObjectGetOwnPropertyDescriptor;
   to["to_complete_property_descriptor"] = ToCompletePropertyDescriptor;
 });
 
 })